dinoprost and Hypertrophy

The present review focuses primarily on the studies we made in recent years to improve the understanding of the molecular mechanisms of PGF2alpha-induced hypertrophy of Vascular Smooth Muscle Cells (VSMC). In this review, we will summarize the recent findings in the context of the PGF2alpha signaling pathway in three parts: PGF2alpha binding to its receptor, transactivation of EGF receptor, two independent signaling transduction pathways increasing the expression of NOX1 gene.

Topics: Activating Transcription Factor 1; Animals; Dinoprost; ErbB Receptors; Gene Expression Regulation; Humans; Hypertrophy; MADS Domain Proteins; MEF2 Transcription Factors; Muscle, Smooth, Vascular; Myogenic Regulatory Factors; NADPH Oxidase 1; NADPH Oxidases; Phosphatidylinositol 3-Kinases; Protein Kinase C-delta; Receptors, Prostaglandin; Signal Transduction; src-Family Kinases; Superoxides; Transcriptional Activation; Up-Regulation

Piperidine-based peroxisome proliferator-activated receptor-α agonists are agents that are efficacious in improving lipid, glycemic, and inflammatory indicators in diabetes and obesity. This study sought to determine whether CP-900691 ((S)-3-[3-(1-carboxy-1-methyl-ethoxy)-phenyl]-piperidine-1-carboxylic acid 4-trifluoromethyl-benzyl ester; CP), a member of this novel class of agents, by decreasing plasma triglycerides, could prevent diabetic nephropathy in the Black and Tan, BRachyuric (BTBR) ob/ob mouse model of type 2 diabetes mellitus. Four-week old female BTBR WT and BTBR ob/ob mice received either regular chow or one containing CP (3 mg/kg per day) for 14 weeks. CP elevated plasma high-density lipoprotein, albuminuria, and urinary excretion of 8-epi PGF(2α), a product of the nonenzymatic metabolism of arachidonic acid and whose production is elevated in oxidative stress, in BTBR WT mice. In BTBR ob/ob mice, CP reduced plasma triglycerides and non-esterified fatty acids, fasting blood glucose, body weight, and plasma interleukin-6, while concomitantly improving insulin resistance. Despite these beneficial metabolic effects, CP had no effect on elevated plasma insulin, 8-epi PGF(2α) excretion, and albuminuria, and surprisingly, did not ameliorate the development of diabetic nephropathy, having no effect on the accumulation of renal macrophages, glomerular hypertrophy, and increased mesangial matrix expansion. In addition, CP did not increase plasma high-density lipoprotein in BTBR ob/ob mice, while paradoxically increasing total cholesterol levels. These findings indicate that 8-epi PGF(2α), possibly along with hyperinsulinemia and inflammatory and dysfunctional lipoproteins, is integral to the development of diabetic nephropathy and should be considered as a potential target of therapy in the treatment of diabetic nephropathy.

Topics: Albuminuria; Animals; Anti-Obesity Agents; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dinoprost; Disease Progression; Female; Glomerular Mesangium; Hypercholesterolemia; Hypertriglyceridemia; Hypertrophy; Hypoglycemic Agents; Hypolipidemic Agents; Insulin Resistance; Kidney; Mice; Mice, Inbred Strains; Mice, Obese; Obesity; Piperidines; PPAR alpha; Propionates

Arachidonic acid (AA) is the metabolic precursor to a diverse range of downstream bioactive lipid mediators. A positive or negative influence of individual eicosanoid species [e.g., prostaglandins (PGs), leukotrienes, and hydroxyeicosatetraenoic acids] has been implicated in skeletal muscle cell growth and development. The collective role of AA-derived metabolites in physiological states of skeletal muscle growth/atrophy remains unclear. The present study aimed to determine the direct effect of free AA supplementation and subsequent eicosanoid biosynthesis on skeletal myocyte growth in vitro. C2C12 (mouse) skeletal myocytes induced to differentiate with supplemental AA exhibited dose-dependent increases in the size, myonuclear content, and protein accretion of developing myotubes, independent of changes in cell density or the rate/extent of myogenic differentiation. Nonselective (indomethacin) or cyclooxygenase 2 (COX-2)-selective (NS-398) nonsteroidal anti-inflammatory drugs blunted basal myogenesis, an effect that was amplified in the presence of supplemental free AA substrate. The stimulatory effects of AA persisted in preexisting myotubes via a COX-2-dependent (NS-389-sensitive) pathway, specifically implying dependency on downstream PG biosynthesis. AA-stimulated growth was associated with markedly increased secretion of PGF(2α) and PGE(2); however, incubation of myocytes with PG-rich conditioned medium failed to mimic the effects of direct AA supplementation. In vitro AA supplementation stimulates PG release and skeletal muscle cell hypertrophy via a COX-2-dependent pathway.

Topics: Animals; Arachidonic Acid; Cell Differentiation; Cell Enlargement; Cell Survival; Cells, Cultured; Cyclooxygenase 2; Dinoprost; Dinoprostone; Hypertrophy; Mice; Muscle Fibers, Skeletal; Signal Transduction

The transcription factor PPARgamma is expressed in endothelium and vascular muscle where it may exert antiinflammatory and antioxidant effects. We tested the hypothesis that PPARgamma plays a protective role in the vasculature by examining vascular structure and function in heterozygous knockin mice expressing the P465L dominant negative mutation in PPARgamma (L/+). In L/+ aorta, responses to the endothelium-dependent agonist acetylcholine (ACh) were not affected, but there was an increase in contraction to serotonin, PGF(2alpha), and endothelin-1. In cerebral blood vessels both in vitro and in vivo, ACh produced dilation that was markedly impaired in L/+ mice. Superoxide levels were elevated in cerebral arterioles from L/+ mice and responses to ACh were restored to normal with a scavenger of superoxide. Diameter of maximally dilated cerebral arterioles was less, whereas wall thickness and cross-sectional area was greater in L/+ mice, indicating cerebral arterioles underwent hypertrophy and remodeling. Thus, interference with PPARgamma signaling produces endothelial dysfunction via a mechanism involving oxidative stress and causes vascular hypertrophy and inward remodeling. These findings indicate that PPARgamma has vascular effects which are particularly profound in the cerebral circulation and provide genetic evidence that PPARgamma plays a critical role in protecting blood vessels.

Topics: Acetylcholine; Animals; Aorta; Arterioles; Cerebrovascular Circulation; Dinoprost; Endothelin-1; Female; Gene Expression Profiling; Genes, Dominant; Hypertension; Hypertrophy; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; PPAR gamma; Serotonin; Serotonin Agents; Signal Transduction; Vasodilator Agents

Prostaglandin F(2alpha) (PGF(2alpha)) is a vasoactive factor that causes constriction and hypertrophy of vascular smooth muscle cells (VSMCs). However, the mechanism of PGF(2alpha)-induced hypertrophy is largely unknown. Cyclic AMP-response element (CRE)-binding protein (CREB), the best characterized stimulus-induced transcription factor, activates transcription of target genes with CRE and promotes cell growth. We examined the role of CREB in PGF(2alpha)-induced hypertrophy of VSMCs. PGF(2alpha) induced phosphorylation of CREB at serine 133, which is a critical marker of activation, after 5-10min of stimulation in a dose-dependent manner. Pharmacological inhibition of extracellular signal-regulated protein kinase and p38 mitogen-activated protein kinase (p38-MAPK) suppressed PGF(2alpha)-induced CREB phosphorylation. Inhibition of epidermal growth factor receptor (EGFR) and mitogen- and stress-activated protein kinase-1 also suppressed PGF(2alpha)-induced CREB phosphorylation. Overexpression of dominant-negative form of CREB (AdCREB M1), of which serine 133 was replaced with alanine, inhibited PGF(2alpha)-induced c-fos mRNA expression as well as hypertrophy of VSMCs [hypertrophy index (microg/10(4)cell); control 8.13, PGF(2alpha) 9.85, AdCREB M1 7.91, and AdCREB M1+PGF(2alpha) 8.43]. These results suggest that PGF(2alpha) activated CRE-dependent gene transcription through EGFR transactivation, and the CREB pathway plays a critical role in PGF(2alpha)-induced hypertrophy of VSMCs.

Topics: Animals; Cells, Cultured; CREB-Binding Protein; Dinoprost; Dose-Response Relationship, Drug; Hypertrophy; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Rats

During hypertrophy the heart increases its utilization of glucose and decreases that of fatty acids, resuming a fetal pattern of substrate metabolism. As demonstrated here, GLUT1 protein expression is increased in association with in vivo pressure-overload-induced hypertrophy. The relationship of changes in GLUT1 to enhanced glucose uptake and to cardiomyocyte hypertrophy and survival is not known. To explore this question we first examined the effect of prostaglandin F2alpha (PGF2alpha), an established hypertrophic agonist, on GLUT1 expression and glucose uptake in neonatal rat ventricular myocytes (NRVMs). PGF2alpha treatment for 24 h led to a fivefold increase in GLUT1 expression and a sixfold increase in glucose uptake. However, NRVMs cultured in the absence of glucose or with 3-O-methyl glucose, a competitive inhibitor of glucose uptake, still exhibited PGF2alpha-induced hypertrophic growth. In addition, we determined that overexpression of GLUT1 using adenovirus was insufficient to cause an increase in cell size, myofibrillar organization, or atrial natriuretic factor (ANF) expression. On the other hand, adenoviral overexpression of antisense GLUT1 (which blocked PGF2alpha-induced increases in GLUT1 protein) prevented PGF2alpha-stimulated cell enlargement and increases in ANF transcription. Overexpression of GLUT1 or addition of PGF2alpha also protected cells against serum deprivation-induced apoptosis; this effect was blocked by antisense GLUT1 but, surprisingly, was not dependent on glucose. Together, these data suggest that upregulation of GLUT1 serves a role in agonist-induced hypertrophy and survival which can be dissociated from its role in glucose transport.

Topics: Adenoviridae; Animals; Aorta; Apoptosis; Atrial Natriuretic Factor; Biological Transport; Blotting, Western; Cell Survival; Cells, Cultured; Dinoprost; Enzyme-Linked Immunosorbent Assay; Glucose; Glucose Transporter Type 1; Hypertrophy; Immunohistochemistry; Male; Mice; Mice, Inbred C57BL; Monosaccharide Transport Proteins; Muscle Cells; Myocytes, Cardiac; Oligonucleotides, Antisense; Pressure; Rats; Rats, Sprague-Dawley; Subcellular Fractions; Time Factors; Up-Regulation

Prostaglandin (PG) F(2alpha), one of the primary prostanoids generated in vascular tissue, is known to cause hypertrophy in vascular smooth muscle cells. To clarify the molecular mechanisms underlying PGF(2alpha)-induced hypertrophy, the involvement of reactive oxygen species was examined in a rat vascular smooth muscle cell line, A7r5. PGF(2alpha) and (+)-fluprostenol, a selective agonist of the PGF receptor, significantly increased intracellular O(2)(-) in A7r5. The PGF(2alpha)-induced O(2)(-) increase was suppressed by diphenyleneiodonium (DPI), an inhibitor of NADPH oxidase that has been reported to be the major source of O(2)(-) in vascular cells. The augmented synthesis of the protein induced by PGF(2alpha) or (+)-fluprostenol was suppressed in the presence of DPI. In PGF(2alpha) or (+)-fluprostenol-treated cells, a dose-dependent increase in the expression of NOX1, a homolog of the catalytic subunit of the phagocyte NADPH oxidase gp91(phox), was demonstrated by Northern blot analysis. Finally, depletion of NOX1 mRNA in the cells transfected with ribozymes targeted for three independent cleavage sites on the mRNA sequence significantly reduced the PGF(2alpha)-induced increase in protein synthesis. Taken together, these results suggest that hypertrophy of vascular smooth muscle cells caused by PGF(2alpha) is mediated by NOX1 induction and the resultant overproduction of O(2)(-) by NADPH oxidase.

Topics: Animals; Base Sequence; Blotting, Northern; Dinoprost; DNA, Complementary; Dose-Response Relationship, Drug; Endothelium, Vascular; Humans; Hypertrophy; Ligands; Molecular Sequence Data; Muscle, Smooth; NADPH Oxidases; Nucleic Acid Conformation; Phagocytosis; Plasmids; Protein Binding; Rats; RNA, Catalytic; RNA, Messenger; Time Factors

Cultured neonatal rat cardiac myocytes have been used extensively to study cellular and molecular mechanisms of cardiac hypertrophy. However, there are only a few studies in cultured mouse myocytes despite the increasing use of genetically engineered mouse models of cardiac hypertrophy. Therefore, we characterized hypertrophic responses in low-density, serum-free cultures of neonatal mouse cardiac myocytes and compared them with rat myocytes. In mouse myocyte cultures, triiodothyronine (T3), norepinephrine (NE) through a beta-adrenergic receptor, and leukemia inhibitory factor induced hypertrophy by a 20% to 30% increase in [(3)H]phenylalanine-labeled protein content. T3 and NE also increased alpha-myosin heavy chain (MyHC) mRNA and reduced beta-MyHC. In contrast, hypertrophic stimuli in rat myocytes, including alpha(1)-adrenergic agonists, endothelin-1, prostaglandin F(2alpha), interleukin 1beta, and phorbol 12-myristate 13-acetate (PMA), had no effect on mouse myocyte protein content. In further contrast with the rat, none of these agents increased atrial natriuretic factor or beta-MyHC mRNAs. Acute PMA signaling was intact by extracellular signal-regulated kinase (ERK1/2) and immediate-early gene (fos/jun) activation. Remarkably, mouse but not rat myocytes had hypertrophy in the absence of added growth factors, with increases in cell area, protein content, and the mRNAs for atrial natriuretic factor and beta-MyHC. We conclude that mouse myocytes have a unique autonomous hypertrophy. On this background, T3, NE, and leukemia inhibitory factor activate hypertrophy with different mRNA phenotypes, but certain Gq- and protein kinase C-coupled agonists do not.

Topics: Adrenergic alpha-Agonists; Animals; Animals, Newborn; Atrial Natriuretic Factor; Cells, Cultured; Dinoprost; Endothelin-1; Fetus; Growth Inhibitors; Growth Substances; Heart; Hypertrophy; Interleukin-1; Interleukin-6; Leukemia Inhibitory Factor; Lymphokines; Mice; Microscopy, Phase-Contrast; Models, Animal; Myocardium; Myosin Heavy Chains; Myosins; Norepinephrine; Phenotype; Phenylalanine; Protein Biosynthesis; Proteins; Rats; RNA, Messenger; Tetradecanoylphorbol Acetate; Triiodothyronine

Myocardial infarction results in focal areas of ischemia, hypoxia, necrosis, and decreased contractile function. To compensate for loss of contractile function, remaining viable myocytes undergo hypertrophic growth. Prostaglandin F2alpha (PGF2alpha), which is released from cells of the myocardium during periods of stress such as hypoxia or ischemia/reperfusion, has recently been shown to stimulate hypertrophic growth in neonatal rat ventricular myocytes. In the present study, we determine which growth-related intracellular pathways are required for PGF2alpha to induce morphological and genetic features characteristic of the hypertrophic phenotype. In cardiomyocytes, PGF2alpha increases the hydrolysis of inositol phosphates and induces the translocation of protein kinase C epsilon to the myocyte membrane, consistent with PGF2alpha receptor coupling to Gq. PGF2alpha also activates the extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase pathways. Surprisingly, studies using pharmacological inhibitors and transfection of dominant-interfering proteins demonstrate that PGF2alpha-induced myocyte hypertrophy occurs independent of either PKC, p38, or ERK pathways. Additional studies demonstrate that PGF2alpha stimulates protein tyrosine phosphorylation and activates c-Jun NH2-terminal kinase and suggest that these pathways mediate hypertrophic growth in response to PGF2alpha.

Topics: Animals; Animals, Newborn; Calcium-Calmodulin-Dependent Protein Kinases; Cells, Cultured; Cyclic AMP; Dinoprost; DNA, Complementary; Enzyme Activation; Enzyme Inhibitors; Flavonoids; Fluorescent Antibody Technique, Indirect; Heart; Heart Ventricles; Hypertrophy; Indoles; Isoenzymes; JNK Mitogen-Activated Protein Kinases; Maleimides; MAP Kinase Kinase 4; Mitogen-Activated Protein Kinase 3; Mitogen-Activated Protein Kinase Kinases; Mitogen-Activated Protein Kinases; Muscle Proteins; Myocardium; p38 Mitogen-Activated Protein Kinases; Phosphatidylinositols; Phosphorylation; Protein Kinase C; Protein Kinase C-epsilon; Protein Kinases; Protein Processing, Post-Translational; Protein Serine-Threonine Kinases; Rats; Rats, Sprague-Dawley; Receptor Protein-Tyrosine Kinases; Receptors, Prostaglandin; Recombinant Fusion Proteins; Signal Transduction; Stress, Physiological; Transfection

The effects of CV-11974, a potent nonpeptide antagonist of the angiotensin II (AII) type-1 receptor (AT1), on cytosolic free calcium concentration ([Ca2+]i), hyperplasia, and hypertrophy of cultured vascular smooth muscle cells (VSMC) from rat aorta were studied. [Ca2+]i was measured by fura 2, and hyperplasia and hypertrophy were determined by incorporation of [3H]thymidine and [3H]leucine, respectively. CV-11974 had no effect on [Ca2+]i itself, but suppressed 10(-7) M AII-induced increase in [Ca2+]i dose dependently at concentrations from 10(-10) M and completely at 10(-7) M. CV-11974 suppressed both Ca2+ release from intracellular Ca2+ stores and Ca2+ influx from the extracellular space. However, CV-11974 had no effect on the increases in [Ca2+]i induced by prostaglandin F2 alpha (PGF2 alpha), a potent vasoconstrictor, or ionomycin, a Ca2+ ionophore. These results indicate that the suppressive effects of CV-11974 act on the binding of AII and its specific receptors. AII 10(-7) M increased the synthesis of DNA and protein to 1.5 and 1.7 times the control values, respectively. CV-11974 had no effect on synthesis of DNA or protein, but suppressed the AII-stimulated synthesis of DNA and protein dose dependently at concentrations > or = 10(-8) and 10(-10) M, respectively and completely at 10(-6) M. These results indicate that AII increases [Ca2+]i and synthesis of DNA and protein in VSMC through activation of AT1. CV-11974 showed no partial agonistic effects on AII. Thus, CV-11974 may act not only as an antihypertensive agent, but also as an inhibitor of vascular injury stimulated by AII.

Topics: Angiotensin II; Angiotensin Receptor Antagonists; Animals; Aorta, Thoracic; Benzimidazoles; Biphenyl Compounds; Calcium; Cells, Cultured; Cytosol; Dinoprost; DNA; Fura-2; Hyperplasia; Hypertrophy; Ionomycin; Muscle Proteins; Muscle, Smooth, Vascular; Rats; Rats, Wistar; Tetrazoles

To more clearly define the physiologic roles of thromboxane (TX)A2 and primary prostaglandins (PG) in vascular tissue we examined vascular contractility, cell signaling, and growth responses. The growth-promoting effects of (15S)-hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5Z,13E-dienoic acid (U46619; TXA2 agonist), PGF2 alpha, and PGE2 consisted of protein synthesis and proto-oncogene expression, but not DNA synthesis or cell proliferation. U46619 contracted rat aortas and increased cultured rat aortic vascular smooth muscle cell intracellular free calcium concentration [Ca2+]i, [3H]inositol monophosphate (IP) accumulation, myosin light chain phosphorylation, and protein synthesis ([3H]leucine incorporation) with EC50 values ranging from 10 to 50 nM. Each of these responses was inhibitable with the TXA2 receptor antagonist [1S]1 alpha,2 beta(5Z),3 beta,4 alpha-7-(3-[2- [(phenylamino)carbonyl]hydrazino]methyl)-7-oxabicyclo[2.2.1]hept-2- yl-5-heptenoic acid (SQ29548). In contrast, PGF2 alpha increased [Ca2+]i, [3H]IP, and protein synthesis with EC50 values of 30-230 nM but contracted rat aortas with an EC50 of 4800 nM. PGE2 increased [Ca2+]i, [3H]IP accumulation, protein synthesis, and contracted rat aortas with EC50 values of 2.5-3.5 microM. TXA2 receptor blockade prevented PGF2 alpha- and PGE2-induced aortic contraction and cell myosin light chain phosphorylation, but not cell signaling or protein synthesis. Binding studies to vascular smooth muscle TXA2 receptors using 1S-[1 alpha,2 beta(5Z),3 alpha(1E,3S),4 alpha]-7-(3-[3-hydroxy-4-(p- [125I]iodophenoxy)-1-butenyl]7-oxabicyclo[2.2.1]hept-2-yl)-5-hepte noic acid ([125I]BOP) showed U46619, SQ29548, PGF2 alpha, and PGE2 competition for TXA2 receptor binding at concentrations similar to their EC50 values for aortic contraction, while binding competition with [3H]PGF2 alpha and [3H]PGE2 demonstrated the specificity of [125I]BOP and SQ29548 for TXA2 receptors. The results suggest that 1) PGF2 alpha- and E2-stimulated vessel contraction is due to cross-agonism at vascular TXA2 receptors; 2) PGF2 alpha stimulates TXA2 receptor-independent vascular smooth muscle protein synthesis at nanomolar concentrations, consistent with an interaction at its primary receptor; and 3) TXA2 is a potent stimulus for vascular smooth muscle contraction and protein synthesis. We suggest that the main physiologic effect of PGF2 alpha may be as a stimulus for vascular smooth muscle cell hypertrophy, not as a contractile agonist.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; Animals; Aorta; Binding, Competitive; Calcium; Cells, Cultured; Cytosol; Dinoprost; Dinoprostone; DNA; Hypertrophy; Inositol Phosphates; Isometric Contraction; Kinetics; Leucine; Male; Muscle, Smooth, Vascular; Prostaglandin Endoperoxides, Synthetic; Prostaglandins; Protein Biosynthesis; Rats; Rats, Sprague-Dawley; Receptors, Prostaglandin; Receptors, Thromboxane; Thymidine; Vasoconstrictor Agents

1. When rats were fed with clenbuterol for 7 days skeletal muscle mass increased by 21% in the tonic soleus and phasic plantaris muscles and a 16% hypertrophy of the heart was also induced. Fenbufen, fed to rats for the same period, blocked the hypertrophy of the heart but not that of the skeletal muscles. 2. When feeding of fenbufen commenced 3 days before the administration of clenbuterol, plasma prosta-glandin F2 alpha (PGF2 alpha) was reduced by 79%; there was again no effect of fenbufen on clenbuterol-induced increases in the RNA or protein content of plantaris, nor in the increased area of fast or slow twitch fibres in the soleus. In the heart the clenbuterol-induced increases in the RNA (+21%) and protein content (+20%) were totally inhibited. 3. The effects of clenbuterol on heart muscle appear to be mediated by a cyclo-oxygenase metabolite of arachidonic acid whilst the effects on skeletal muscle are not.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Cardiomegaly; Clenbuterol; Cyclooxygenase Inhibitors; Diet; Dinoprost; Glycolysis; Hypertrophy; Male; Muscle Proteins; Muscles; Organ Size; Oxidation-Reduction; Phenylbutyrates; Rats; RNA

Endogenous prostaglandins (PGs) have been isolated in large amounts from the gastrointestinal tract of man. These substances are intimately related to muscle contraction and cytoprotection. The gastric juice and serum levels of PGE2 and F2 alpha have been assayed in nine infants with infantile hypertrophic pyloric stenosis (IHPS) and seven age-matched controls. The gastric juice levels were significantly raised in the IHPS group for both PGE2 (P = 0.001) and PGF2 alpha (P = 0.02) as compared to controls. The possible role of PGs in the etiology of IHPS is discussed.

Topics: Dinoprost; Dinoprostone; Female; Gastric Acidity Determination; Humans; Hypertrophy; Infant; Male; Prostaglandins E; Prostaglandins F; Pyloric Stenosis; Sex Factors